Hi Waghuldey,
Refer below query.
Database
For this example I have used of Northwind database that you can download using the link given below.
Download Northwind Database
SQL
SELECT EmployeeID Id,FirstName,City,Country FROM Employees
WHERE BirthDate
BETWEEN REPLACE(REPLACE(REPLACE(REPLACE('12th Dec 1948','st',''),'nd',''),'rd',''),'th','')
AND REPLACE(REPLACE(REPLACE(REPLACE('1st Jan 1966','st',''),'nd',''),'rd',''),'th','')
Output
Id FirstName City Country
2 Andrew Tacoma USA
3 Janet Kirkland USA
5 Steven London UK
6 Michael London UK
7 Robert London UK
8 Laura Seattle USA